<?php

    /**
     * PHPExcel_CalcEngine_Logger
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_Calculation
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    class PHPExcel_CalcEngine_Logger {
        /**
         * Flag to determine whether a debug log should be generated by the calculation engine
         *        If true, then a debug log will be generated
         *        If false, then a debug log will not be generated
         * @var boolean
         */
        private $writeDebugLog = false;
        /**
         * Flag to determine whether a debug log should be echoed by the calculation engine
         *        If true, then a debug log will be echoed
         *        If false, then a debug log will not be echoed
         * A debug log can only be echoed if it is generated
         * @var boolean
         */
        private $echoDebugLog = false;
        /**
         * The debug log generated by the calculation engine
         * @var string[]
         */
        private $debugLog = [];
        /**
         * The calculation engine cell reference stack
         * @var PHPExcel_CalcEngine_CyclicReferenceStack
         */
        private $cellStack;

        /**
         * Instantiate a Calculation engine logger
         * @param  PHPExcel_CalcEngine_CyclicReferenceStack $stack
         */
        public function __construct(PHPExcel_CalcEngine_CyclicReferenceStack $stack) {
            $this->cellStack = $stack;
        }

        /**
         * Return whether calculation engine logging is enabled or disabled
         * @return  boolean
         */
        public function getWriteDebugLog() {
            return $this->writeDebugLog;
        }

        /**
         * Enable/Disable Calculation engine logging
         * @param  boolean $pValue
         */
        public function setWriteDebugLog($pValue = false) {
            $this->writeDebugLog = $pValue;
        }

        /**
         * Return whether echoing of debug log information is enabled or disabled
         * @return  boolean
         */
        public function getEchoDebugLog() {
            return $this->echoDebugLog;
        }

        /**
         * Enable/Disable echoing of debug log information
         * @param  boolean $pValue
         */
        public function setEchoDebugLog($pValue = false) {
            $this->echoDebugLog = $pValue;
        }

        /**
         * Write an entry to the calculation engine debug log
         */
        public function writeDebugLog() {
            //    Only write the debug log if logging is enabled
            if ($this->writeDebugLog) {
                $message       = implode(func_get_args());
                $cellReference = implode(' -> ', $this->cellStack->showStack());
                if ($this->echoDebugLog) {
                    echo $cellReference, ($this->cellStack->count() > 0 ? ' => ' : ''), $message, PHP_EOL;
                }
                $this->debugLog[] = $cellReference . ($this->cellStack->count() > 0 ? ' => ' : '') . $message;
            }
        }

        /**
         * Clear the calculation engine debug log
         */
        public function clearLog() {
            $this->debugLog = [];
        }

        /**
         * Return the calculation engine debug log
         * @return  string[]
         */
        public function getLog() {
            return $this->debugLog;
        }
    }
